The present invention relates to laser source detection, and more particularly, to a system and method for laser source detection.
Modern weapons systems frequently use lasers to assist in targeting. Because the path of a laser beam is essentially a straight line, it can be used as a starting point for sighting a weapon, and adjustments may be made to compensate for gravity, wind, and other factors. Some weapons systems employ a beam-riding scheme, in which a munition, such as a missile, tracks the path of a laser beam to a target painted by the laser. One of the effects of laser-assisted targeting is improved accuracy and precision.
At the same time, a party painted by such a laser needs to be able to react in a quick and appropriate manner. Regardless of whether the source of the laser is an enemy or friendly party, the painted party needs to avoid any munitions that may be fired. If the source of the painting laser is a friendly party, the painted party will preferably be identified as a non-enemy, and no munitions will be fired. “Friendly-party notification” is becoming increasingly important, as friendly-fire incidents are making up increasingly larger percentages of total wartime casualties.
One approach similar to friendly-party notification is CIDDS (Combat IDentification Dismounted Soldier). In CIDDS, an interrogator set shines a laser on a target. If the targeted soldier is friendly and has a similar system, laser detectors will decode the signal and a radio transmitter on the targeted soldier responds with a coded message indicating he or she is friendly. This response message breaks radio silence, and thus, is a security risk. The CIDDS system is strictly a combat identification system, and does not detect or respond to lasers from range finders, battlefield illuminators, or target designator systems. The CIDDS helmet-mounted transponder is about 335 grams and has a range of approximately 1100 meters.
Another approach that provides a greater range (about 5500 meters ground-to-ground and 8000 meters air-to-ground), but is much heavier, is BCIS (Battlefield Combat Identification System). This vehicle-mounted system operates similarly to, but is not compatible with, CIDDS. Because communication responses are by radio, radio silence is broken. While BCIS is capable of identifying the source of a laser within a quadrant, it is still primarily a combat identification system, and does not detect or respond to lasers from range finding systems, battlefield illuminators, or target designator systems. Other similar systems, such as LWS-CV, also exist.
A technology that may improve laser detection capabilities is HARLID (High Angular Resolution Laser Irradiance Detector). While still primarily a prototype system, HARLID uses an array of detectors to locate the source of a laser within one degree (azimuth and elevation). However, HARLID is purely a detection system and provides no combat identification or reciprocal targeting capabilities. Raytheon's AN/VVR-1 Laser Warning Receiver may be an example of a HARLID-based system.
Other approaches have been developed to detect target designator, range finder, and beam rider threats, but actions taken upon detection (e.g. friendly-party notification) still suffer from shortcomings. To improve battlefield situation awareness, it would be desirable to accurately detect if a soldier or vehicle has been painted by a laser (e.g. range finder, target designator, beam rider, spotting beam, battlefield illuminator), locate the source of the laser, and provide friendly-party identification/notification. In addition, it would be desirable, in some embodiments, to provide reciprocal targeting to respond to imminent threats. The preferred solution should be relatively lightweight, easy-to-deploy, small, and interfaceable with existing systems, such as situation awareness systems (e.g. Objective Force Warrior displays and vehicle cockpit display systems) and target designators.